Heating system



' April 26, 1949. H. E. MORTON HEATING SYSTEM Filed June 13, 1947 A v M7 M v w a [r y j 7 9 1 #7 v m m IN VEN TOR.

WK) E Morrow BY QMJ E724,

Patented Apr. 26, 1949 UNITED STATES; PATENT OFFICE HEATING SYSTEM HarryE. Morton, Hyde Park, Mass. Application June 13, 1947, Serial No.754,493

2 Claims. 1

This invention relates to steam heating systems, and has an object tomaintain heat in the radiators of such systems during the periods of thethermostats in the heated spaces are not calling for heat.

In an intermittently fired, one-pipe, steam heating system, such, forexample, as one fired by an oil burner, the radiators usually get coldbefore the burner, started by an indoor thermostat, can heat the boilersufliciently to again supply steam to the radiators. This results in theradiators being alternately hot and cold, and in discomfort during theofi periods of the burner when the outdoor temperatures are relativelylow.

This invention provides controls for an intermittently fired steamheating system, which results in steam being supplied to the radiatorsof the system during the off periods of the burner at low outdoortemperatures, thereby providing comfort equal to that provided by aconventional, hot water heating system.

The invention will now be described with reference to the drawing whichillustrates diagrammatically, a one-pipe, steam heating system embodyingthis invention.

The conventional boiler 5 fired by a conventional oil burner 6 driven byan electric motor I, supplies steam through the pipe 8 to a radiator 9having a conventional vent valve 20.

The motor I is connected to be started and stopped by the conventionalcontrol in which responds to the temperature of the boiler water, and bythe conventional control thermostat II which responds to the temperatureof the space heated by the radiator 9.

The steam pipe 8 contains the valve I! which acts as a vacuum breakerand which has the air bleed port lB therein. The port I8 is opened andclosed by the piston I!) which responds to negative pressures in theboiler, and the opening or down movement of which is opposed by a spring20. The port H in the valve I2 communicates with a closed chamber which,itself communicates with the atmosphere through the port l3. The piston14 closes the port l3 and is movable by the hydraulic bellows IS. Thebellows I5 is connected by the tube Hi to a conventional thermostat Hwhich is exposed to the temperature of the outdoor air.

' It is obvious that when the port I3 is not closed by the piston I4,the port I8 will be opened to the atmosphere by the down movement of thepiston l9. When the port I3 is closed by the atmosphere even though thepiston is moves downward.

At one specific setting the thermostat I! may be adjusted to cause thebellows l5 to move the piston l4 toopen the port l3 at outdoor airtemperatures above 34 F. and to close the port H at outdoor temperaturesbelow 34 F'.

The piston I9 and the spring 20 may be ad: justed to open the port I8when the negative pressure in the boiler reaches 10" of mercury.

The control I 0 which may be a conventional "Aquastat may be adjusted tomaintain the boiler water at a mean temperature of about 175 F.,

The indoor thermostat ll may be adjusted to attempt to maintain adesired indoor temperature of F.

In operation the thermostat Il may call for heat and start the burner 6to create steam in the boiler 5 and expel all air from the systemthrough the valve 20. When the temperature surrounding the indoorthermostat l 1 reaches 75, the burner 6 will be stopped. Steam will condense throughout the system, creating a negative pressure in all partsabove the water level in the boiler. When this negative pressure reaches10" of mercury the piston l9 will move downwardly to open the port Hi.If the outdoor temperature is above 34 F., the port i3 will be open, andconsequently, the entire system will be vented to the atmosphere throughthe ports l8 and IS. The port l8 will remain open until the pressureWithin the system stabilizes at 10 of mercury, negative pressure. As thenegative pressure increases, the boiling point of the water in theboiler 5 drops so that vapor is continuously formed and the heat ofevaporation can be obtained from the heat stored in the system. Theboiling point at 10" of mercury is 193 F.

If the temperature surrounding the outdoor thermostat i1 is below 34 F.,the port l3 will be closed by the piston I4, and although the port l8may be opened as the negative pressure increases in the boiler, therecan be no venting and no air will be bled into the boiler. The negativepressure in the boiler will continue to increase beyond 10" of mercuryuntil the pressure equals 16.4 of mercury which corresponds to thetemperature. At this point the Aquastat It) will start the motor I andthe burner 6, thus adding heat to the water and causing more steam toflow to the radiator 9. The continued operation of the burner will raisethe temperature of the water to the cut-off temperatureof the control l0which piston H, the port i8 will not be opened to the I will again stopthe motor.

' escapee It should be clear that valve [2 as described, will permit theheating system to operate as a vacuum system with a negative pressurewhich does not increase above of mercury whenever the outdoortemperature is greater than 34 F., thus producing the desirablehold-over characteristic necessary for this moderate temperature whenthe burner is stopped. The valve I: will also cause the system to act asa vacuum system when the outdoor temperature is less than 34 F. andmaintain steam in the system during the periods when the burner is notoperating.

It should be further understood that the above selected outdoortemperatures and water temperatures may be varied to suit the climaticconditions as they exist.

While one embodiment of the invention has been described for the purposeof illustration, it should be understood that the invention is notlimited to the exact apparatus and arrangement of apparatus illustrated,as modifications thereof may be suggested by those skilled in the artwithout deparature from the essence of the invention.

What is claimed is:

1. A steam heating system comprising a boiler, a heat producer forheating the boiler, a radiator in the space to, be heated and connectedto the boiler, a thermostat responsive to the temperature of said spacefor energizing said heat producer, means responsive to the temperatureoi the boiler water for energizing said heat producer for maintainingthe water at a predetermined minimum temperature, an air bleeding valveconnected to the boiler, an outdoor thermostat, and means including saidoutdoor thermostat and including means responsive to pressure changes intheboiler for maintaining a predetermined negative pressure in theboiler and for actuating said l the boiler water for energizing saidheat producer for maintaining the water at a predetermined minimumtemperature, an air bleeding valve connected to the boiler, a port insaid valve for bleeding air into the interior thereof, means includingan outdoor air thermostat for opening and closing said port for bleedingair into said valve at outdoor temperatures above a predeterminedtemperature, a second port in said valve connecting the interior thereofwith the interior of the boiler, and means responsive to changes in thepressure above the water level in the boiler tor opening and closingsaid second port for maintaining a predetermined negative pressure insaid boiler.

HARRY E. MORTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED S TATES PATENTS Number Name Date 616,575 Jamer Dec. 27, 18981,921,708 Snavely Aug. 8, 1933 2,249,706 Ferguson July 15, 1941

